GREEN
HOUSE
Greenhouse
A greenhouse
(also called a glasshouse) is a building where plants are grown These structures range in size from small sheds to very large buildings A miniature greenhouse is known as a cold frame
Greenhouse
A greenhouse is a structure with different types of covering materials such as a glass or plastic roof and frequently glass or plastic walls it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants soil and other things inside the building Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall In addition the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red to which glass is partly opaque so some of this energy is also trapped inside the glasshouse However this latter process is a minor player compared with the former (convective) process Thus the primary heating mechanism of a greenhouse is convection This can be demonstrated by opening a small window near the roof of a greenhouse the temperature drops considerably This principle is the basis of the autovent
automatic cooling system Thus the glass used for a greenhouse works as a barrier to air flow and its effect is to trap energy within the greenhouse The air that is warmed near the ground is prevented from rising indefinitely and flowing away
Although there is some heat loss due to thermal conduction through the glass and other building materials there is a net increase in energy (and therefore temperature) inside the greenhouse
Greenhouses can be divided into glass greenhouses and plastic greenhouses Plastics mostly used are PEfilm
and multiwall sheet in PC
or PMMA Commercial glass greenhouses are often high tech production facilities for vegetables or flowers The glass greenhouses are filled with equipment like screening installations heating cooling lighting and may be automatically controlled by a computer
UsesGreenhouses protect crops from too much heat or cold shield plants from dust storms and blizzards and help to keep out pests Light and temperature control allows greenhouses to turn inarable land into arable land there by improving food production in marginal environments
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Greenhouse
A greenhouse
(also called a glasshouse) is a building where plants are grown These structures range in size from small sheds to very large buildings A miniature greenhouse is known as a cold frame
Greenhouse
A greenhouse is a structure with different types of covering materials such as a glass or plastic roof and frequently glass or plastic walls it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants soil and other things inside the building Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall In addition the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red to which glass is partly opaque so some of this energy is also trapped inside the glasshouse However this latter process is a minor player compared with the former (convective) process Thus the primary heating mechanism of a greenhouse is convection This can be demonstrated by opening a small window near the roof of a greenhouse the temperature drops considerably This principle is the basis of the autovent
automatic cooling system Thus the glass used for a greenhouse works as a barrier to air flow and its effect is to trap energy within the greenhouse The air that is warmed near the ground is prevented from rising indefinitely and flowing away
Although there is some heat loss due to thermal conduction through the glass and other building materials there is a net increase in energy (and therefore temperature) inside the greenhouse
Greenhouses can be divided into glass greenhouses and plastic greenhouses Plastics mostly used are PEfilm
and multiwall sheet in PC
or PMMA Commercial glass greenhouses are often high tech production facilities for vegetables or flowers The glass greenhouses are filled with equipment like screening installations heating cooling lighting and may be automatically controlled by a computer
UsesGreenhouses protect crops from too much heat or cold shield plants from dust storms and blizzards and help to keep out pests Light and temperature control allows greenhouses to turn inarable land into arable land there by improving food production in marginal environments
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
A greenhouse is a structure with different types of covering materials such as a glass or plastic roof and frequently glass or plastic walls it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants soil and other things inside the building Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall In addition the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red to which glass is partly opaque so some of this energy is also trapped inside the glasshouse However this latter process is a minor player compared with the former (convective) process Thus the primary heating mechanism of a greenhouse is convection This can be demonstrated by opening a small window near the roof of a greenhouse the temperature drops considerably This principle is the basis of the autovent
automatic cooling system Thus the glass used for a greenhouse works as a barrier to air flow and its effect is to trap energy within the greenhouse The air that is warmed near the ground is prevented from rising indefinitely and flowing away
Although there is some heat loss due to thermal conduction through the glass and other building materials there is a net increase in energy (and therefore temperature) inside the greenhouse
Greenhouses can be divided into glass greenhouses and plastic greenhouses Plastics mostly used are PEfilm
and multiwall sheet in PC
or PMMA Commercial glass greenhouses are often high tech production facilities for vegetables or flowers The glass greenhouses are filled with equipment like screening installations heating cooling lighting and may be automatically controlled by a computer
UsesGreenhouses protect crops from too much heat or cold shield plants from dust storms and blizzards and help to keep out pests Light and temperature control allows greenhouses to turn inarable land into arable land there by improving food production in marginal environments
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Although there is some heat loss due to thermal conduction through the glass and other building materials there is a net increase in energy (and therefore temperature) inside the greenhouse
Greenhouses can be divided into glass greenhouses and plastic greenhouses Plastics mostly used are PEfilm
and multiwall sheet in PC
or PMMA Commercial glass greenhouses are often high tech production facilities for vegetables or flowers The glass greenhouses are filled with equipment like screening installations heating cooling lighting and may be automatically controlled by a computer
UsesGreenhouses protect crops from too much heat or cold shield plants from dust storms and blizzards and help to keep out pests Light and temperature control allows greenhouses to turn inarable land into arable land there by improving food production in marginal environments
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
UsesGreenhouses protect crops from too much heat or cold shield plants from dust storms and blizzards and help to keep out pests Light and temperature control allows greenhouses to turn inarable land into arable land there by improving food production in marginal environments
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Because greenhouses allow certain crops to be grown throughout the year greenhouses are increasingly important in the food supply of high latitude countries One of the largest greenhouse complexes in the world is in Almeria Spain where greenhouses cover almost 50000
acres (200
km2) Sometimes called the sea of plastics
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Greenhouses are often used for growing flowers vegetables fruits and tobacco
plants Bumblebees
are the pollinators
of choice for most greenhouse pollination although other types of bees
have been used as well as artificial pollination Hydroponics
can be used in greenhouses as well to make the most use of the interior space
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Besides tobacco many vegetables and flowers are grown in greenhouses in late winter and early spring and then transplanted outside as the weather warms Started plants are usually available for gardeners
in farmers markets
at transplanting time Special greenhouse varieties of certain crops such as tomatoes are generally used for commercial production
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
The closed environment of a greenhouse has its own unique requirements compared with outdoor production Pests
and diseases and extremes of heat and humidity have to be controlled and irrigation
is necessary to provide water Significant inputs of heat and light may be required particularly with winter production of warm-weather vegetables
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Because the temperature and humidity of greenhouses must be constantly monitored to ensure optimal conditions a wireless sensor network
can be used to gather data remotely The data is transmitted to a control location and used to control heating cooling and irrigation systems[1]
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
History
Cucumbers
reached to the ceiling in a greenhouse in Richfield Minnesota where market gardeners grew a wide variety of produce for sale in Minneapolis ca 1910
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
19th Century Orangerie in Weilburg GermanyThe idea of growing plants in environmentally controlled areas has existed since Roman
times The Roman emperor Tiberius
ate a cucumber-like[2]
vegetable daily The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year Cucumbers were planted in wheeled carts which were put in the sun daily then taken inside to keep them warm at night[3]
The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite
(aka lapis specularis) according to the description by Pliny the Elder[4]
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Giant greenhouses in the NetherlandsThe first modern greenhouses were built in Italy
in the 13th century[5]
to house the exotic plants that explorers brought back from the tropics They were originally called giardini botanici (botanical gardens) The concept of greenhouses soon spread to the Netherlands
and then England along with the plants Some of these early attempts required enormous amounts of work to close up at night or to winterize There were serious problems with providing adequate and balanced heat in these early greenhouses Today the Netherlands has many of the largest greenhouses in the world some of them so vast that they are able to produce millions of vegetables every year
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
The French botanist Charles Lucien Bonaparte
is often credited with building the first practical modern greenhouse in Leiden Holland to grow medicinal tropical plants[citation needed]
bull
Originally on the estates of the rich with the growth of the science of botany greenhouses spread to the universities The French called their first greenhouses orangeries since they were used to protect orange trees from freezing As pineapples became popular pineries or pineapple pits were built Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved The greenhouse at the Palace of Versailles
was an example of their size and elaborateness it was more than 500
feet (150
m) long 42
feet (13
m) wide and 45
feet (14
m) high
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
In the nineteenth Century the largest greenhouses were built The conservatory at Kew Gardens
in England is a prime example of the Victorian greenhouse Although intended for both horticultural
and non-
horticultural exhibition these included Londons Crystal Palace the New York Crystal Palace
and Munichrsquos Glaspalast Joseph Paxton who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth in Derbyshire working for the Duke of Devonshire designed and built the first Londons Crystal Palace A major architectural achievement in monumental greenhouse building were the Royal Greenhouses of Laeken
(1874ndash1895) for King Leopold II of Belgium
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
The Netherlands
bull
The Netherlands has some of the largest greenhouses in the world Such is the scale of food production in the country that in 2000 greenhouses occupied 10526 hectares or 025 of the total land area of the Netherlands[6]
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
Since 2000 technical innovations include the closed greenhouse a completely closed system allowing the grower complete control over the growing process while using less energy Floating greenhouses are used in watery areas of the country
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers efficiently producing euro45 billion worth of vegetables fruit plants and flowers some 80 of which is exported
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Ventilation
is one of the most important components in a successful greenhouse If there is no proper ventilation greenhouses and their plants become prone to a myriad of problems
Greenhouse ventilation
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Ventilation serves four major purposes within the greenhouse
1
Regulating the temperature
2
Ensurance of plenty of fresh air to photosynthesize
3
Good ventilation prevents pest infestations
4
Encouraging important pollination within the greenhouseIn greenhouses recirculation fans can be used in parallel or series ventilation
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Basic mechanismbull
The Earth receives energy from the Sun in the form UV visible and near IR
radiation most of which passes through the atmosphere
without being absorbed Of the total amount of energy available at the top of the atmosphere (TOA) about 50 is absorbed at the Earths surface Because it is warm the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards that radiated downwards is absorbed by the Earths surface This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
The solar radiation
spectrum for direct light at both the top of the Earths atmosphere and at sea level
bull
The incoming radiation from the Sun is mostly in the form of visible light and nearby wavelengths largely in the range 02ndash4
μm corresponding to the Suns radiative temperature of 6000
K[13]
Almost half the radiation is in the form of visible light which our eyes are adapted to use[14]
bull
About 50 of the Suns energy is absorbed at the Earths surface and the rest is reflected or absorbed by the atmosphere The reflection of light back into spacemdashlargely by cloudsmdash
does not much affect the basic mechanism this light effectively is lost to the system
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
The absorbed energy warms the surface Simple presentations of the greenhouse effect such as the idealized greenhouse model show this heat being lost as thermal radiation The reality is more complex the atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for window bands) and most heat loss from the surface is by sensible heat
and latent heat
transport Radiative energy losses become increasingly important higher in the atmosphere largely because of the decreasing concentration of water vapor an important greenhouse gas It is more realistic to think of the greenhouse effect as applying to a surface in the mid-troposphere which is effectively coupled to the surface by a lapse rate
bull
Within the region where radiative effects are important the description given by the idealized greenhouse model becomes realistic The surface of the Earth warmed to a temperature around 255
K radiates long-wavelength infrared
heat in the range 4ndash100
μm[13]
At these wavelengths greenhouse gases that were largely transparent to incoming solar radiation are more absorbent[13]
Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers To maintain its own equilibrium it re-radiates the absorbed heat in all directions both upwards and downwards This results in more warmth below while still radiating enough heat back out into deep space from the upper layers to maintain overall thermal equilibrium Increasing the concentration of the gases increases the amount of absorption and re-radiation and thereby further warms the layers and ultimately the surface below[9]
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
Greenhouse gasesmdashincluding most diatomic gases with two different atoms (such as carbon monoxide CO) and all gases with three or more atomsmdashare able to absorb and emit infrared radiation Though more than 99 of the dry atmosphere is IR transparent (because the main constituentsmdashN2 O2 and Armdash
are not able to directly absorb or emit infrared radiation) intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other non-IR-
active gasesbull
The simple picture assumes equilibrium In the real world there is the diurnal cycle
as well as seasonal cycles and weather Solar heating only applies during daytime During the night the atmosphere cools somewhat but not greatly because its emissivity is low and during the day the atmosphere warms Diurnal temperature changes
decrease with height in the atmosphere
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
Earth Talk Building a Green Economy
bull
From the Editors of EThe Environmental Magazine
bull
Dear EarthTalk What does it mean when one uses the phrase ldquobuilding a green economyrdquo Irsquove heard it repeated a few times lately and would like to have a better understanding of the concept
ndash Rosie Chang Islip NYbull
The phrase ldquobuilding a green economyrdquo
means different things to different people but in general it refers to encouraging economic development that prioritizes sustainabilitymdashthat is working with nature and not against it in the quest to meet peoplesrsquo
needs and wantsmdashinstead of disregarding environmental concerns in the process of growing the economy The primary way governments around the world are trying to ldquogreenrdquo
their own economies today is by increasing investment inmdashand by extension creating jobs inmdashindustries on the cutting edge of non-polluting renewable forms of energy such as solar and wind power
bull
President Obama has repeatedly invoked his vision of a green economy as a tool for helping the US lift itself out of recession and position itself as an economic powerhouse in a carbon-constrained future
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
The American Recovery and Reinvestment Act (ARRA) of 2009 the $7872 billion stimulus package that Congress signed into law in 2009 was chock full of provisions to boost renewable energy energy efficiency and environmental restoration initiatives Examples include $45 billion to convert government buildings into high-performance green buildings $84 billion for investments in public transportation and tens of billions of dollars more for research into new technologies to amplify existing efforts ARRA also earmark $11 billion for the implementation of the ldquosmart gridrdquo
a new approach to power distribution that will bring more clean energy sources into the mix and promote energy efficiency
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
Of course Americans arenrsquot the only ones bent on building a green economy During the 1980s and 1990s while the American government was largely asleep at the wheel on environmental issues countries such as Denmark Germany Spain and Japan were already busy investing in wind and solar research and implementation And while these nationsrsquo
ongoing efforts are nothing to sneeze at economists point out that what is most needed is action on the part of the worldrsquos fastest growing economiesmdash
China and India
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
A recent report by the consulting firm McKinsey amp Company found that Chinamdashwhich surpassed the US as the worldrsquos largest generator of greenhouse gases three years agomdashhas great potential for building a green economy over the coming decades According to McKinsey by 2030 China could reduce its oil and coal imports by up to 40 percent and its greenhouse gas emissions by 50 percent by investing upwards of 15 trillion yuan
($220 billion in US dollars) per year in both existing and new green technologies China has begun to see the light with regard to reducing emissions increasing energy efficiency and embracing renewable alternative energy but it has yet to make significant financial commitments which will be key to both warding off catastrophic climate change and building a truly global green economy
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial
bull
CONTACTS ARRA wwwrecoverygov McKinsey amp Company wwwMcKinseycom
SEND YOUR ENVIRONMENTAL QUESTIONS TO EarthTalkreg co E ndash
The Environmental Magazine PO Box 5098 Westport CT 06881 earthtalkemagazineco
m E is a nonprofit publication
Subscribe wwwemagazinecomsubs
cribe Request a Free Trial Issue wwwemagazinecomtrial